Exhaust seepage???

[popeyecahn]

Exhaust seepage into cabin???

I've been smelling this for the past week, it seems like when I've set the recirc button to fresh air intake I can smell something akin to exhaust. Fan on or not btw.

I had thought originally that maybe it was another car since I had been following an older vehicle that looked like it may have been producing its fair share of exhaust fumes, but the more I drive, the more I'm convinced it's coming from the CX-5!

The thought occurred that maybe it's just part of the "new car smell" and of course I'd like to think that but CO being the killer that it is has me concerned. Maybe I should put a carbon monoxide detector in the car?

I ran a test while on an errand. I set it for recirc, opened the windows for a few blocks and then rolled them up for a few more blocks, no exhaust odor. Then I switched from recirc to fresh air and within a minute I had the odor. I did this again on my way home with the same effect. Hmmmm

 

[GAXIBM]

On fresh the air comes in just below the winshield on the passenger side...

 

[popeyecahn]

Thanks for the info, it was suggested to idle the car after it had warmed up and sniff around for leaks (front of car, underneath, under the hood etc), which is something I'll do tomorrow. It's also possible something has dropped onto the exhaust somewhere and emits a similar smell, and granted plastic and such can produce odd smells.

I wanted to see if anyone else had a similar experience, since if I cannot come to any conclusion, I'll need to have it looked in short order.

 

[andyg]

I like the idea of using a CO detector. Its a very dangerous gas as you know so the detector would be a more definitive answer than sniffing around. I would say bring it to the dealer but I doubt they would know how to do a proper test and they would just tell you its fine. If you have a battery operated CO detector, great, if not you can use an electric one from your home plugged in with an extension cord in your driveway.

 

[SayNoToPistons]

Chances are if there is an exhaust leak, you would most definitely hear it before smelling it. Especially if it's before the cat.

 

[popeyecahn]

Chances are if there is an exhaust leak, you would most definitely hear it before smelling it. Especially if it's before the cat.

Hmmm yeah I think you're right about that, it hadn't occurred to me. My wrenching experience stopped at 70's british bikes and Swedish wagons and a lot has happened since then lol

 

[GAXIBM]

Check your rear door latch and seals, if you are getting exaust gas it is likely comming through the rear door...

 

[popeyecahn]

Check your rear door latch and seals, if you are getting exaust gas it is likely comming through the rear door...

Yeah know... I noticed that the hatch didn't always close quite as solidly as I thought it should. So just now I played with the latch adjustment some to snug in the closure after looking at the seals and such, as well as using some Armor All to coat the door side to see where it may or may not be contacting, which was a little difficult. There may have been a few areas that didn't quite make a perfect seal.

I'll say this, I wasn't too impressed with the rubber gasket itself, it doesn't seem to be very generous in terms of size, seal design and coverage. It needs to be a bit more rounded and buoyant feeling me thinks.

So would having the recirc to cabin only create a positive cabin pressure and vice versa?

 

[GAXIBM]

Recirc limits the air comming in under the windshield which may invite air leaks to be inbound from other arears. Outside air puts a bit of pressure in the cabin which makes most of the air leaks to be outbound from the cabin assuming all windows closed. In cold weather and slightly warm I use outside air but I switch to recirc when it is really hot and humid outside so the AC can dehumidify the inside air more easily.

 

[SayNoToPistons]

^ This. It is impossible to get a tight seal obviously. Even with the HVAC to recirc as there is plenty of exterior air pressure when the vehicle is in motion. The HVAC duct flaps have a somewhat loose tolerance by design and are only sealed with foam.

 

[popeyecahn]

Recirc limits the air comming in under the windshield which may invite air leaks to be inbound from other arears. Outside air puts a bit of pressure in the cabin which makes most of the air leaks to be outbound from the cabin assuming all windows closed. In cold weather and slightly warm I use outside air but I switch to recirc when it is really hot and humid outside so the AC can dehumidify the inside air more easily.

Kind of like when one is driving a vehicle with a roll-down back window, the tailpipe smell gets worse once you open any side windows.

In regular weather I use fresh air intake to moderate the cabin climate and then I'll hit recirc in cold weather to warm up the cabin quicker, the same (but reverse temp of course) with the AC. And on that note have you (OR ANYONE) noticed that the heater seems to take a while to come up to temp?

Since I bought my CX-5, the temps here in SD have been pretty cold so I hadn't using the fresh air in, hence the problem having shown up with the warmer temps last week or so...

 

[popeyecahn]

^ This. It is impossible to get a tight seal obviously. Even with the HVAC to recirc as there is plenty of exterior air pressure when the vehicle is in motion. The HVAC duct flaps have a somewhat loose tolerance by design and are only sealed with foam.

So there must be some threshold that is met then. Heck I could try the same experiment with the recirc on and opening a window a crack instead of the fresh air intake. That said, I think adjusting the rear latch may have sorted things. Further testing is needed to confirm (like when I'm not ferrying children or commuting to work).

BTW, thanks to both of you for your input.